Fabrication of superhydrophobic surfaces via CaCO3 mineralization mediated by poly(glutamic acid)

Surfaces with micrometer and nanometer sized hierarchical structures were fabricated by an one-step in situ additive controlled CaCO3 mineralization method. After chemical modification, the surfaces with various morphologies showed superhydrophobicity in different states, which could be easily adjusted by the initial supersaturation of the mineralization solution (concentration of calcium ion and poly(glutamic acid)). Generally, the “lotus state” surface which was covered by a thick layer of tetrahedron-shaped CaCO3 particles to exhibit a contact angle (CA) of 157±1° and a very low contact angle hysteresis (CAH) (roll-off angle=1°) was produced under high supersaturation. On the other hands, the petal-like surface with flower-shaped calcite spherulites was obtained in a relative low supersaturation, which showed both high CA (156±2°) and CAH (180°) in a “Cassie impregnating wetting state”.

The superhydrophobic surfaces with the controllable micro- and nanostructure could be constructed in one-step via polypeptide mediated in situ mineralization of CaCO3 combined with chemical modification.Figure optionsDownload as PowerPoint slideHighlights
► Superhydrophobic surfaces were fabricated by a one-step mineralization method.
► PGlu11 acted as additive and pre-treatment of substrate was essential for mineralization.
► The surfaces morphology of CaCO3 was controllable.
► The superhydrophobic state was affected by the topology of mineralized surface.